L.A. County and California health officials say they will look into the case. It's the first confirmed case in the Southern California industry since 2004, when production was closed for four weeks.

An actress who works in Southern California's pornography industry has tested positive for HIV, renewing county and state health officials' concerns that the adult entertainment industry lacks sufficient safety measures to prevent the spread of AIDS and other sexually transmitted diseases.

The new case was confirmed to The Times and pornography industry websites Wednesday by the Adult Industry Medical Healthcare Foundation, a San Fernando Valley-based clinic that serves adult-film stars in Sherman Oaks and Granada Hills. Public health officials, however, said no official report had been made at the state or county level.

Dr. Jonathan Fielding, health officer for Los Angeles County, said Wednesday that his office was launching an investigation.

Officials from the state Division of Occupational Safety and Health also said they will look into the circumstances of the case, which is the first publicly confirmed HIV infection in Southern California's porn industry since 2004, when an HIV outbreak shut down production for four weeks.

At that time, a porn actor who had returned from working in Brazil spread the virus to three actresses who had performed with him. A transsexual performer unrelated to the other cases also tested positive.

In the latest case, HIV tests of the woman's partners have been negative for the virus, according to Adult Industry Medical Healthcare Foundation officials. Those partners are not being allowed to perform at this time and are being encouraged to test again in 14 days, said Brooke Hunter, the clinic's administrator.

"This is really not a major event," Hunter said, adding that the infected actress had worked "very infrequently."

Sharon Mitchell, the clinic's founder, told AVN, an adult industry website, that the clinic had recently changed its policies on disclosure of new cases. "What we do is just handle everything privately unless there's a widespread problem," she said.

As the clinic downplayed the positive test, public health officials cited their ongoing battle with the porn industry over the use of condoms during filming. The two sides have been at odds for years, and despite the intense scrutiny, Fielding said he is concerned that condoms are still not being used.

"You wouldn't send someone to work on a high-rise building without a hard-hat, so why are we allowing these performers to perform without condoms?" Fielding said.

Deborah Gold, a senior safety engineer with the state Occupational Safety and Health Division, said her agency repeatedly had attempted to crack down on unsafe workplaces in the adult entertainment industry, issuing several citations against employers, including a gay male production company that touted its condom-free filming.

Despite those efforts, she said, numerous investigations have found that condoms were not used and that no training had been conducted to prevent unsafe contact.

Los Angeles County has been receiving reports from the clinic of 60 to 80 new cases of chlamydia and gonorrhea a month among adult performers, Fielding said.

The clinic's testing protocol recommends that adult performers get screened for HIV every 30 days. Fielding called that schedule insufficient to protect against transmission because it takes nine to 11 days after exposure for HIV to appear on test results.

"Let's say you were infected on Monday, tested on Wednesday and perform on Friday. You would show up as negative, but you're not negative," Fielding said.